Telegraphy is the long-distance transmission of textual/symbolic messages without the physical exchange of an object bearing the message.

Telegraphy requires that the method used for encoding the message be known to both sender and receiver. Such methods are designed according to the limits of the signaling medium used. The use of smoke signals, beacons, reflected light signals, and flag semaphore signals are early examples.

An electrical telegraph was independently developed and patented in the United States in 1837 by Samuel Morse.